AC Not Cooling? 7 Things to Check Before Calling for Repair

Giron & Son's Heating & Cooling • Southern Illinois

When your air conditioner is running but the house is still warm, the cause can be as simple as a thermostat setting or as serious as a refrigerant or compressor problem. Before scheduling service, there are a few safe checks you can make.

1. Check the thermostat

Make sure it is set to Cool and the setpoint is below the current room temperature. If the thermostat uses batteries, replace weak batteries.

2. Look at the air filter

A heavily clogged filter can restrict airflow and contribute to poor cooling or an iced evaporator coil. Replace a dirty disposable filter with the correct size and type.

3. Check the supply vents

Confirm that supply registers are open and not blocked by furniture, rugs or curtains. Weak airflow throughout the home can point to a filter, blower or duct issue.

4. Check the outdoor unit

With the system calling for cooling, look and listen from a safe distance. If the outdoor unit is not operating, the system may need professional diagnosis. Do not open electrical panels.

5. Look for ice

Ice on the refrigerant tubing or indoor coil area is not normal. Turn cooling off and allow the system to thaw. Continuing to run a frozen system can make the problem worse.

6. Check the breaker once

If an HVAC breaker is tripped, you can reset it once. If it trips again, leave it off and call for service rather than repeatedly resetting it.

7. Consider the outdoor conditions

On extremely hot Illinois days, a system may run for long periods. But if indoor temperature keeps climbing or the air from the vents is not cool, the equipment should be checked.